Automatic sizing device for grinding machines



July 17, 1928. 1,677,307

' A. P. STEINER AUTOMATIC SIZING DEVIFCE FOR GRINDING MACHINES Filed May 7, 1925 s Sheets-Sheet 1 Po wsn Lines INVENTQR Amos 'P Steiner A. P. STEINER AUTOMATIC SIZING DEVICE FOR GRINDING MACHINES July 17, 1928.

Filed'lliay v, 1925 5 Sheets-Sheet 2 INVENTOR AmosP Steiner AT-roR'wEY I 5 Sheets-Sheet July 17, 1928. 1

A. P. STEINER AUTOMATIC SIZING DEVICE FOR GRINDING MACHINES FiledMay 7, 1925 IN VENTO R Amos P Steiner ATTORNEY m .Jul HH U I hM-UHH IIHHHHu -I 'II ILII L. I I l I I I July 17, 1928.

Filed May 1925 5 Sheets-Sheet 4 July w, 292%, 1,677,307

A. P. STEENER AUTGMATIC SIZING DEVICE FOR GRINDING MACHINES Filed May "2, 192 5 5 Sheets-Sheet 5 gwvenfoz AmosP. Steiner Patented July 1928 J UN T PATENT. OFFICE.

AMOS r. srninnn, or wayunsnono, PiinNsYLvAnia, AssmNon ro' nanmsgoo'r. cour- RANY, or WAYNESBOBO, PENNSYL ANIA, a CORPORATION;OEPENNSYLVANIA.

* AUTOMATIC SIZINGDEVICE roaenninme MAcn INE's."

Applieation'filed ma 7,1925. Serial No. 28,719.

My said invention relates to an automatic sizing device for grinding machines in com-. bination with a feed control for such machines. The predominant object 'of the in- 1 h vention is to bring the work automatically to the exact size desired without any attention or assistance of the operator. In fur.- tl1erance of this pbject I provide means whereby the sizing of the work is effected by W a constant fixed weight operated by gravity, uninfluenced by any outside or personal force that would produce varying results. The usual method of -measuring work is affected b tlie touch or "feel of different, operators which also varies in the same operator at different times. 'The action of a springis also not completely reliable, as th s yaries in power at different points of'deflect'ion.

Another object is to provide means whereby two or' more sizes can be obtained or measured ,with 'the same device, as by one gauging means for the-first or rough size and another later-acting one for the finish- 1 ing size. Others may be added if necessary.

Another object is to provide electrical contacts that have a' wide gap when open and niake a complete contact very quickly, eliminating the usual slow moving contacts that burn and fuse the contact points, thus rendering the device inaccurate. (7

Another ob' ect -'s to make the first or roughing cut with a heavy or. coarse feed, and when the roughing size is completed, to change automatically to a fine or light feed for reducing slowly to the finished size. Another object is-to provide for a variable amount of time during which the traversing elements of the machine. traverse back and- 40' forth to bring the work to a round exact size and to grind or spark out and produce a high class finishor polish on the work. This amount of time is easily and quickly adjusted by a smallthumb screw or valve.

Another object is to provide for backing .the wheel away from the work'quickl'y after the work is finished thus allowing plenty of roomfor the operator to remove the finished work and put in a new piece. The distance the wheel-is fed back is adjustable for different amounts that maybeleft on the work to be groundofi'.

Another objectis to asset a signal in the personal equation due tovariation in the form of a light or bell or other device to notify the operator ofthe completion of the operation or cycle,--'s o.he' may give his attention to running two or more machines.

Another object is to provide means Whereby operation of the tail stock for removal of the finished work, will return the sizing device and latch it in position in readiness for the next piece to be ground. Referring to the accompanying wh ch are made a part hereof and on which sim lar reference characters indicate similar parts Figure. general arrangement,f Figure '2, an assembly plan of thetail stock and the sizing device on alarger scale,

drawings,

1, is an assembly plan showing the I l Figure 3, a side elevation of a lever on the tail stock, with parts in section, F1gure'4, a fragmentary side elev of the tail stockspindle and parts connected thereto,

Figure 5, a side elevation of the sizing device,

.vice',

F gure 7 a horizontal section-of the sizing device showing operating parts,

of the valve mechanism shown in Figure 9,

i and I Figure 1-1, a side elevation of the feed reducing bar. Y Y

In the drawings reference rlicates a Wheel base,,11 a gri ding wheel, .12 a tail stock and 13 a piece of work tobe ground,.the work being supported by work centers 14 or'in'any other suitable manner.

The wheel and work may reciprocaterelat velyzgtgtone another or not, "according to circums'ta'n es, and the work revolves in the direction of the arrow in Figure 5, all in a manner that is well-known to those familiar with the'construction ofgrinding machines.

As clearly shown in Fig. 2 the sizing de; vice, which. is similar in certain respects to -that,shownin my (lo-pending application F No. 7 57 ,27 9 filed December 20,,v 1 924, is mounted 0!. $115 ta 5 k 12 bill o iou ly ation Figure 6, a rear elevation of the sizing de- Figure 8, a plan of the wheel feed mech the construction could be varied by mounting it on the\ tab1e or other part of the ma shaft also carries a gage 15.

' forward end 'tion by lock nuts 22.

chine, all without departing from the spirit of the .invention. A circuit closer is mounted on a shaft 16 (Figs. 6 and 7) which The shaft is supported for rocking movement in bearings 17., 17., here shown as ball bearings, said bearings being mounted in recesses in the walls of casin 18. The gage 15' has at its ngers 19 and 20 holding diamonds 21 and 22. These fingers are mounted at different levels for alternate engagement with the work and are adjustable by means of screws 21 held in adjusted posi- The gage 15 has a rearwardly extending arm serving as a lever for lifting the diamonds out of position manually when desired.

The circuit closer 15 is provided at its free end with'a pair of contacts 23 and 24 for closing a pair of electric circuits. The contact 23 operates in conjunction with the upper diamond 21. When the work is reduced sufficiently to allow said diamond to pass under the influence of gravity, the contact 23- moves into engagement with a pairof re-' silient stationary contacts indicated at 23" (Figs. 5 and 7) closing a circuit by means of which the feed is changed from a roughing to a finishing feed as hereinafter described. When the finishing operation has also passes the wor far the lower. diamond under. the influence of gravity as above. described and permits the proceeded suflicientliy circuit closer to move thus bringing the convin tact 24 into engagement with resilient sta;

tionary contacts indicated at 24 and closing a second circuit to stop the feed. Circuit closing devices of other types may obviously be substituted for those shown in the draw- It will be noted thatthe diamonds are set at different distances from the work center, the lower diamond being farthest from its center of oscillatio'nvand being held at first by the swell or curve of the work belowga plane passing through the axis of the work and the axisyof the gage 15', the Work being of course larger than the desired size. 7 As the work decreases in size the weight of the forwardly extending arms of the gage and the circuit closer (the lower side of Fig. 1 being taken as the front of the machine) acts on the diamonds with. auniform forceto ,jcause them to rise until the diamond 21 sired.

The casing 18 is adjustable and from the work by means of a screw 27 having a graduated dial 28 for indicating in A latch 29 (Figs. 5 and 6)- engages the forwardly extending arm of the gage to hold. itand'the circuit closer out of working position. Below the circuit closer I have provided a shaft 31' carrying a. cam for engagement with a cam face at 30 on the circuit-closer. This shaft also carries a rockarm 32 (Figs. 4 and 5) connected to the tail stock spindle 33 by a link 33'. y

The tail stock has an operatin lever 34 (Figs. 2 and 3) having a pin an slot connectionat 34" with the tail stock spindle. This lever carries a spring-pressed detent 35 adapted to engage a notch 36 in a fixed plate 37 which dete-nt can be retracted by pressure on the thumb latch 58.

A pull on the lever 34 bringing it into the position indicated in dotted lines at B in Figure 2 moves the work center 14 back to release the work 13. This movement also,

by means of link'33 and arm 32 turns the 'ment with the latch 29 by means of which it is held in raised position to maintain the diamonds out of the way of the work. When the lever 34. is moved to release the work, as

above described, the detent 35 engages the notch in plate 37 thereby holding the lever in place and consequently holding the work center in retracted position. When the operator has now inserted a new piece of work he has but to press the latch 38 and release the lever whereupon the center enters the I work to be ground and holds it in place.

The latch 29 ma-y now be caused to release" the gage by pressure exerted against-the laterally extending pin 39 or the arm may be held up by the latch until the grinding wheel 7 has taken enough of a cut to present a smooth surface for contact by the first diamond 21.

'The feeding means for the'wheel is shown in Figs. 1, 8, 9, 10, 11 and said meansfcomprises an armlike frame member 40 supporting a ratchet 41. A-pawl 42 engages? the ratchet said pawl being mounted on a rockarm 43 actuated at appropriate intervals in any suitable manner in the operation of the machine as for instance at the end of each stroke of the reciprocating carriage. A screw 44 limits the movement of the arm in one direction andthis-screw may be adjusted to vary the length of the stroke and thus change the extent of movement of the ratchet. The feed of the wheel toward the work is controlled in any suitable manner in accordance with the rotation of the ratchet. A detent pawl 45 engages the ratchet to hold it against reverse movement as it is advanced by the pawl-42. A weight 46 is suspended from the ratchet bymeans of a cable 47 and this tends to return the ratchet to its original position.

My invention includes means for changing the feedingvmovement ofthe wheel in addition to the adjusting means 44, the additional feed change being desirable foir changing from a feed such as is desirable for rough grinding to a feed such as is desirable for a finishing action and consisting pref- 1 erably of a radical reduction in the feed at a single step.

This mechanism comprises a slide bar 48 mounted in a bearing in the frame m'ember and impelled in one direction by a spring 49 (Fig. 8) which tends to throw it into the position indicated in Fig. 11 where the rockarm is permitted to move to its fullest extent except as limited by the'position of the screw 44. This provides a feed suitable, e. g. for rough grinding. When such a change is desired, as for example to a limited feed desirable for finishingf grindlng, the feed is reduced by diminishing the movement of the arm 43. In the present embodiment of the invention this takes place through the sizing 'device above described when the work reaches such a size as to permit the diamond 21 to pass and thus closes at 23 the energizing circuit of the magnet through the conductors 51 and,52. The

electromagnet thereupon attracts its armature which consistsof the enlarged head at the left end of the slide bar 48 and draws the slide bar to the left into a position 'in which the enlarged end -48 of the bar comes into the path of the rockarm 43 to limit its return movement thus limiting its operative stroke and therefore'the feeding movement of the wheel. The extent of change in the arcof oscillation is subject to variation by adjustment of the screw 44 which determines .the maximum stroke of the arm.

After the diamond 21 has passed the work .as above described the operation of the machine continues at a finishing feed until the I second diamond 22 passes the work allowlng the longer arms of the gage and circuit closer to move downward whereupon another circuit is closed by engagement of the contacts 24 and 24.

This circuit is the energizing circuit for the electromagnet and includes conductors 53 and 54. When the electromagnet 55 is energized it lifts the pawl 42 out of engagement. with the ratchet 41 and thus stops the feed, Detent pawl 45 being still in engagement with the ratchet holds it against reverse movement whilethe grinding wheel continues to travel l back and forth producing a' true surface and a 'high polish on'the work.

The :pawl 42 is provided withf-a contact 57 which engages a'djacent termmals on a valve stem.

pair of eana etrs' '59 and so when an; pawl is attracted by the electromagnet 55. This closes a"eircuit which includes the energizing coilf'ot"anelectromagnet'58 and the electromagiiet58' thereupon attracts its ar'mature UL whichfeonsists of the enlarged head of a I balanced eaten valve 61. [This valve is slidably mounted in a casing 70 and may be positioned soiasi to admit oil from a feed pipe 62 througln the casing to an outlet port 63' or else tolpermitit to escape byway of a port 68'. YVlien'the valve is in position to admit pressure fluid through the "port 63 the piston 64 will be raised in its cylinder 72 (not shown) in the feed pipe 62. The slow.

movement allows time for the operation of finishing and polishing the work, as above referred to, and continues until the piston passes the opening of the feed pipe GG'Whichis not restricted in its delivery of liquid to the cylinder 65 and therefore quickly raises piston 64 to disengage the detent 45.

' The feed'retardin weight 46 at the end of its fall strikesj a, fiat face-on a bent lever 67'having forks at 67 engaging a-pin on the stem of valve 61'. The momentum of the weight'causes it 'to withdraw thehead of the valve from the magnet 58 and moves it into the position indicated in Figure 10 closing the feed pipe .62 and opening the exhaust port 68 to permit the pressure fluid to escape. The'spring 69 in -the casing 72 acts on the piston 64 to return it to the bottom of its casing this spring being strong enough to overcome the pressure of the oil in pipe 66 and to force the oil out through ports 63 and 68. When the piston reaches. its original position it cuts off the flow from pipe 66 as-shown in Fig. 10.

An adjustable. stop 71 .(Fig. 10) is positioned to limit -the movement of the lever 67 under" the impetusgivento it by the weight 46. This stop l fhas a stem'71' slidably mounted in a bracket'72 on afixed part of the machine frame. A set screw 73 serves to hold the stem in ,adjusted ,position. This'device prevents damage to the valve in that it prevents-the full force of the weight from being transmitted to the A'port 74"i'sprovided in t-he casing 72 back of the piston to drain ofli' any oil that might get back of the piston and interfere which may get back of the piston 61' and thus might interfere with its movement.

A signaling device 76 here shown as an electrielight but which may take the form of an audible or other signal is shown as and described in the specification but onlyinterposed in the conductor 59 in Fig. 9. This is shown for convenience as if it were suspended on -the conductor but ordinarily will be mounted on a fixed support such as the frame member 40 -(Fig. 8).

The operation of the device may bebriefly described as comprising six steps or stages,

the first step .being that in which' the wheel is fed in rapidlywhile grinding the work roughly to size. The second step is that during which the wheel is fed in slowly to finish the grinding. The third step is that in which the wheel is not fed in but the relative traverse of the wheel and the work continues as well as their relative rotation.

' During this time a finish or polish is given to the work. The fourth step is that in which the wheel backs away to provide room forchanging the work. The foregoing steps take lace automatically and as the fifth step tile operator is notified by a signal that the operation is complete, such a signal being here indicated as being given by a light. The sixth step, whichis the only manual one, consists in retracting the foot stock by means of the lever 34, thus simultaneously breaking the circuits and bringing the diamonds to a low point below the position indicated in Figure 5. A new piece of work is now placed between the centers and the operation is repeated. Asabove explained the gage may at once be released from the hook 29 or may be left there until the work has been ground sufficiently to provide a smooth surface for the engagement of the first diamond.

- It will be obvious to those skilled in the art that various changes may be made in my device without departing from the spirit of the invention and therefore I do not limit myself to what is shown in the drawings as indicated in the appended claims.

Having thus fully described my Said invent-ion, what I claim as new and desire to secureby Letters Patent, is:

1. In a grinding machine, a wheel, a rotary workholder, a diameter gage having an arm swingable on a pivot parallel to the axes of the wheel and the workholder said armbeing longer than the distance between its pivot and the unfinished work and being iased to move past said work, means for retracting a work center to release the work, and connections therefrom to move the, gage into'idle position remote from the work, substantially as set forth. i

2. In a grinding machine, awheel, a rotary workholder, a diameter ga e having an arm swin'gable on a *pivot parallel to the axesof the wheel and the workho lder said arm being longer than the distance between-- its pivot and the unfinished'work and being biased to move past said work, means for retracting a work center to release the work, connections therefrom for moving the gage into idle position remote from the work, and means whereby the gage may be moved into such position independently of such retracting means, substantially'as set forth.

3. In a grinding machine, a wheel and a workholder, traversing means for one of said devices, means for feeding one toward "the other for a roughing out, means to reduce the rate of feed for a finishing out, means to stop the feed while continuing the traversing movement to polish the work, and means thereafter to move one of said devices away from the other? substantially as set forth.

4. Ina grinding machine, an abrading device, a Workholder, means for feeding one toward the other, means for stopping the feed including a ratchet, an operating pawl therefor, a gage for the work, connections from the gage to the pawl fordisconnecting it from the ratchet at a predetermined time,

a detent for the 'ratchet, means for withdrawing the detent from the ratchet upon completlon of the grinding operation includmg a fiuld motor, means operated on disconnecton, of said operating pawl for admitting fluid pressure to said motor, and means actlng'upon withdrawal of said detent to space the abrading device from the workholder, substantially as set forth.

5. A grinding machine as in claim 4, said means for spacing the abrading device from the workholder comprising a disk fixed to said ratchet, a cable passing about said disk,

and a weight on said cord, substantially as set forth.

6. A grinding machine as in claim 4, havmg a valve controlling said fluid pressure, a lever for operating the valve, a disk fixed to sald ratchet, a cable passing about said disk, and a weight on the cable for turning the ratchet backward to space the abrading device from the workholder said valve-op- I path of .said

forth. an abrading deolder, means for feeding one on*withdrawal of the detent to space the pletion of the grinding operation, and means operated on withdrawal of said detent to space the abrading means from the workholder, substantially as set forth.

8. In a grinding machine, an abrading device, a workholder, means for feeding one toward the other, means for stopping the feed including a ratchet, an operating pawl therefor, a gage for the work, connections from the gage to the pawl for disconnecting it from the ratchet at a predetermined time, a detent for the ratchet, means for with drawing the detent from the ratchet upon completion of the grinding operation including a fluid motor, means operated on disconnection of said operating pawl for admitting fluid pressure to said motor with a delayed action whereby the abrading de- Vice may polish the work while the feeding operation is intermitted, and means acting abrading device from the workholder, subsubstantially as set forth.

- 9. A grinding machine as in claim 4, said connectmns from the gage to the operating pawl including a normally-open electric circuit, an electromagnet for the pawl in said circuit, a second normally-open circuit, a contact on the pawl for closing the second circuit, an electromagnet in the circuit, a valve to admit pressure fluid to the fluid motor, and a part on said valve serving as an armature for the second electromagnet, substantially as set forth.

10; A grinding machine as in claim 8, with a 'valve for reducing the fluid pressure, means acting to close said valve aftersaid spacing operation, and means to return the movable element of said fluid motor upon reduction of such pressure, substantially'as set forth. 11. In a grinding machine, a wheel and a workholder, means including a gravity-operated gage controlled by the size of the work for feeding one toward the other for a roughing cut, means operated by said age to reduce the rate of feed for a finis ing' cut, means to polish the work, and means thereafter-to move one of said devices away from the other, substantially as set forth.

In Witness whereof, I have hereunto set my hand at Waynesboro, Pennsylvania this 5th day of May, A. D. nineteen hundred and twenty-five. I

AMOS P. STEINER. 

